For service calls made by a person to the City relating to the sewer system, there shall be a charge as set by resolution of the City Council to the person requesting the service for time spent after normal business hours (including all time spent on weekends and holidays), if the service call relates to that portion of the sewer system which the person is responsible for under 95.05 of this Code of Ordinances. These charges shall commence at that time it was first determined that the service call related to that portion of the sewer system which the person is responsible for under Section 95.05.